/Engine/Source/Runtime/NavigationSystem/Public/NavigationData.h
DECLARE_DELEGATE_OneParam(FPathObserverDelegate, FNavigationPath*);.
typedef TMulticastDelegate_TwoParams< void, [FNavigationPath](API\Runtime\NavigationSystem\FNavigationPath) *, [ENavPathEvent::Type](API\Runtime\Engine\AI\Navigation\ENavPathEvent__Type) > FPathObserverDelegate